Could you please attach the polling and/or building log when this issue happens?

In some previous versions of the plugin, all vobs were mounted before starting dynamic views. It raised some issues with configurations where there are a lot of vobs.

As a workaround, I would recommend you to have a script that mount all vobs on startup.

this is how the build log looks when the issue occurs.

Started by user anonymous
Building remotely on dcrtl02.eplmain.eplinc.com
[PLSQL3.5.0] $ cleartool desc -fmt %[found_bls]Xp\n stream:PLSQL_3.5.0_Int@\EPL_Projects
baseline:PLSQL3.4.0.30@\EPL_Projects
[PLSQL3.5.0] $ cleartool desc -fmt %[latest_bls]Xp\n stream:PLSQL_3.5.0_Int@\EPL_Projects
baseline:PLSQL3.5.0.74@\EPL_Projects
[PLSQL3.5.0] $ cleartool desc -fmt %[component]Xp\n baseline:PLSQL3.5.0.74@\EPL_Projects
component:PLSQL@\EPL_Projects
[PLSQL3.5.0] $ cleartool desc -fmt %[root_dir]p\n component:PLSQL@\EPL_Projects
\PLSQL
[PLSQL3.5.0] $ cleartool lsview clearcase_cm_PLSQL_3.5.0_int

• clearcase_cm_PLSQL_3.5.0_int \\dcrtl02.eplmain.eplinc.com\ccstg\clearcase_cm_PLSQL_3.5.0_int
  [PLSQL3.5.0] $ cleartool startview clearcase_cm_PLSQL_3.5.0_int
  [PLSQL3.5.0] $ cleartool desc -fmt %[found_bls]Xp\n stream:PLSQL_3.5.0_Int@\EPL_Projects
  baseline:PLSQL3.4.0.30@\EPL_Projects
  [PLSQL3.5.0] $ cleartool desc -fmt %[component]Xp\n baseline:PLSQL3.4.0.30@\EPL_Projects
  component:PLSQL@\EPL_Projects
  [clearcase_cm_PLSQL_3.5.0_int] $ cleartool pwv -root
  [PLSQL3.5.0] $ cleartool lsview clearcase_cm_PLSQL_3.5.0_int
• clearcase_cm_PLSQL_3.5.0_int \\dcrtl02.eplmain.eplinc.com\ccstg\clearcase_cm_PLSQL_3.5.0_int
  [PLSQL3.5.0] $ cleartool startview clearcase_cm_PLSQL_3.5.0_int
  [clearcase_cm_PLSQL_3.5.0_int] $ cleartool lshistory -all -since 14-dec-10.21:18:01utc+0000 -fmt '\"%Nd\" \"%u\" \"%En\" \"%Vn\" \"%e\" \"%o\" \"%[activity]p\" \n%c\n' -branch brtype:PLSQL_3.5.0_Int -nco PLSQL
  cleartool: Error: Unable to access "PLSQL": No such file or directory.
  FATAL: UCM ClearCase failed. exit code=1
  [PLSQL3.5.0] $ cleartool lsview clearcase_cm_PLSQL_3.5.0_int
• clearcase_cm_PLSQL_3.5.0_int \\dcrtl02.eplmain.eplinc.com\ccstg\clearcase_cm_PLSQL_3.5.0_int
  [PLSQL3.5.0] $ cleartool rmview -force -tag clearcase_cm_PLSQL_3.5.0_int
  Removing references from VOB "\EPL_Projects" ...
  Removed references to view "\\dcrtl02.eplmain.eplinc.com\ccstg\clearcase_cm_PLSQL_3.5.0_int" from VOB "\EPL_Projects".
  [PLSQL3.5.0] $ cleartool mkview -stream PLSQL_3.5.0_Int@\EPL_Projects -tag clearcase_cm_PLSQL_3.5.0_int \\dcrtl02.eplmain.eplinc.com\ccstg\clearcase_cm_PLSQL_3.5.0_int
  Created view.
  Host-local path: dcrtl02.eplmain.eplinc.com:\ccstg\clearcase_cm_PLSQL_3.5.0_int
  Global path: \\dcrtl02.eplmain.eplinc.com\ccstg\clearcase_cm_PLSQL_3.5.0_int
  Attached view to stream "PLSQL_3.5.0_Int".
  [PLSQL3.5.0] $ cleartool startview clearcase_cm_PLSQL_3.5.0_int
  [PLSQL3.5.0] $ cleartool setcs -tag clearcase_cm_PLSQL_3.5.0_int -stream
  [PLSQL3.5.0] $ cleartool lsproject -view clearcase_cm_PLSQL_3.5.0_int -fmt %[mod_comps]Xp
  component:PLSQL@\EPL_Projects[PLSQL3.5.0] $ cleartool mkbl -identical -comment hudson-PLSQL3.5.0-75 -incremental -view clearcase_cm_PLSQL_3.5.0_int -comp PLSQL@\EPL_Projects PLSQL3.5.0.75
  Created baseline "PLSQL3.5.0.75" in component "PLSQL".
  Begin incrementally labeling baseline "PLSQL3.5.0.75".
  Done incrementally labeling baseline "PLSQL3.5.0.75".
  [PLSQL3.5.0] $ cleartool lsstream -view clearcase_cm_PLSQL_3.5.0_int -fmt %[latest_bls]Xp
  baseline:PLSQL3.5.0.75@\EPL_Projects[PLSQL3.5.0] $ cleartool lsbl -fmt %[component]Xp PLSQL3.5.0.75@\EPL_Projects
  component:PLSQL@\EPL_ProjectsNo emails were triggered.
  [PLSQL3.5.0] $ cmd /c call C:\DOCUME~1\CLEARC~2\LOCALS~1\Temp\hudson707444540875171592.bat

You should have a script to mount required vobs on the windows machine startup.